This subsection explains the format of an interface definition language (IDL) used in an IDL file. An interface definition consists of the following:

• Interface definition header
  An interface definition header defines entire interface specifications.
  
• Interface definition body
  An interface definition body defines individual type and operation specifications. The interface definition body consists of the following four declarations:
  

  Import declaration

  Constant declaration

  Type declaration

  Operation declaration

A parameter declaration is included in the operation declaration.

The declaration in the interface definition body is validated if specifications in the interface definition header and interface definition body are inconsistent.

Interface definition header

[[interface_attribute,...]] interface interface_name

Interface definition body

{ import-declaration constant-declaration type-declaration operation-declaration parameter-declaration }